Is it better to tank with seal of insight (for the free healing)since we dont have any threat problem or keep up the seal of truth for the damage it does ?So in other words i am asking Making healers life easier with seal of insight or kill the boss faster with seal of truth up ?

Missing attacks should not generate Holy Power. We generally don’t reward characters for failing to land attacks. Retribution paladins can improve their hit or expertise like other melee DPS specs do. Tanks don’t generally stack a lot of hit or expertise, but we think Protection paladins will still be able to tank just fine. Prot warriors for example miss Shield Slams.

Before this "fix" I would have agreed with many tanks that once initial threat is established (an opening of Wings, Divine Plea for full holy power, Judgment for possible Sacred Duty proc, and Shield of the Righteous, make for a solid opening maneuver, btw) that switching to the healing seal makes perfect sense, especially for progression content, where every ounce of healing counts. However, since holy power isn't generating at a linear pace anymore, I find my rotation broken up by periods of monitoring my holy power progression. The threat decrease isn't a concern of significant note, the interruption of my tanking chi is, because I hate using a pally slam with only 2 HP.

See, if you're like me, then your threat stats probably suck. Because, honestly, they're not required. With the Vengeance buff making hits mean twice as much as those made without it, so long as threat is established at the beginning, only truly exceptional dps should be approaching you on threat. However, with Seal of Truth adding to the bulk of my expertise, my missed Crusader Strikes are very evident on bosses with Seal of Insight. And so my Holy Power is only accumulating at around 75% of the rate I was accustomed to, and of course, is dependent on RNG.

So in heroics, where I almost exclusively used Seal of Insight, (making the amount of heals I needed fairly minimum) I know have reversed it to almost always using Truth. Burst dps is the name of the game in heroics, and without steady Holy Power, I can't maintain a proper tanking pace. Raids, it depends on the fight. For anything with a dps and/or tank swap, I can usually stick to Insight, but Magmaw, for instance, is just a fight where I need that burst threat.

TL;DRHoly Power is dependent on hitting mobs now, so getting threat stats is semi-relevant just to keep a proper "flow" to your rotation. Heal when you really gotta, but I like keeping my flow steady as much as possible.

just use seal of insight unless you have threat problems .as a paladin tank you won't put out dps numbers even with SOT .i have tanked till 2 hc modes for both 10/25 with seal of insight even after our fix nerf my threat remains same thanks to other buffs like CS , and for progress every little thing you can help out healers is nice.thats just my 2c